rendering attributes

README.md

@@ -50,6 +50,8 @@ func enumerateLineFragments(with provider: NSTextElementProvider, block: (NSText
 func characterIndexes(within rect: CGRect) -> IndexSet
 var visibleCharacterIndexes: IndexSet
 func boundingRect(for range: NSRange) -> CGRect?
+
+func setRenderingAttributes(_ attributes: [NSAttributedString.Key : Any], for range: NSRange)
 ```
 
 ### `NSRange` and `NSTextRange` Additions

Sources/Glyph/NSTextRange+NSRange.swift

@@ -73,6 +73,20 @@ extension NSTextRange {
 
 		self.init(location: start, end: end)
 	}
+
+	convenience init?(_ range: NSRange, provider: NSTextElementProvider) {
+		let docLocation = provider.documentRange.location
+
+		guard let start = provider.location?(docLocation, offsetBy: range.location) else {
+			return nil
+		}
+
+		guard let end = provider.location?(start, offsetBy: range.length) else {
+			return nil
+		}
+
+		self.init(location: start, end: end)
+	}
 }
 
 #endif

Sources/Glyph/NSTextView+Additions.swift

@@ -49,4 +49,28 @@ extension TextView {
 #endif
 	}
 }
+
+extension TextView {
+	/// Apply attributes that do not affect layout, if supported by the text system.
+	public func setRenderingAttributes(_ attributes: [NSAttributedString.Key : Any], for range: NSRange) {
+		// first determine if TK2 is enabled, so we do not downgrade
+		if #available(macOS 12.0, iOS 16.0, *), let textLayoutManager = textLayoutManager {
+			guard
+				let contentManager = textLayoutManager.textContentManager,
+				let textRange = NSTextRange(range, provider: contentManager)
+			else {
+				return
+			}
+
+			textLayoutManager.setRenderingAttributes(attributes, for: textRange)
+
+			return
+		}
+
+#if os(macOS)
+		layoutManager?.setTemporaryAttributes(attributes, forCharacterRange: range)
+#endif
+	}
+}
+
 #endif